Interactive television reception and transmitting processes and associated devices

ABSTRACT

A method for activating several applications, where a received start up application determines whether a first application or a second application will be activated. The first application, which is received, along with the start up application, is activated if a file of additional data is not present in a memory. Conversely, the second application will be activated if the file is present in the memory.

This application claims the benefit, under 35 U.S.C. §365 ofInternational Application PCT/EP03/50678, filed Oct. 2, 2003, which waspublished in accordance with PCT Article 21(2) on Apr. 15, 2004 inEnglish and which claims the benefit of French patent application No.0212412, filed Oct. 7, 2002.

FIELD OF THE INVENTION

The invention relates to an interactive television system. It is moreparticularly applicable to the cases where the television receptionsystem is connected to a domestic digital network. It is thereforeconcerned in particular with a system comprising means of interactivedigital television transmission and user stations or terminals forreception of interactive digital television.

The invention applies equally to a standardized interactive digitaltelevision system (Multimedia Home Platform or MHP standard, forexample) as to a proprietary system (such as that implemented by theOpenTV company for example).

BACKGROUND OF THE INVENTION

Devices are known in the art which make provision for the recording, bymeans of decoders, of interactive programmes. The latter subsequentlyenable a user to interact, during the viewing of an application. Forexample, the document WO-01/50763 discloses the automatic recording ofan auxiliary programme according to preset criteria, with a view tosubsequent use by the user. Document WO-00/76213 relates to a priorrecording of a software application, then of a television programmecorresponding to the moment of its broadcasting, with appropriatemarkings for the interactivity relating to this application and theoption for the user to trigger the interactive programme.

In interactive digital television systems, the broadcaster provides theterminal with a digital stream. This stream contains multiplexed datawhich make it possible to reconstruct the initial streams: for examplevideo streams, audio streams, signalling data and interactiveapplication.

For reasons of broadcasting cost and of downloading time, thebroadcasters and providers of services tend to minimize the size of theapplications. An effect of this is the non-existence of applicationsthat contain additional content such as real-time video sequencesenhancing broadcast programmes. Now, the use of these sequences may bevery beneficial for the production of interactive adverts for example.

The prior downloading to the terminal of sophisticated applications canbe envisaged, and may make it possible for data which it would beimpractical, or even impossible, to download with the stream broadcastupon the triggering of an application to be made available locally.However, such an approach requires a coherent system that executes in arather complex way, since it is necessary to organize a priordownloading of the applications into all the receivers concerned. Inpractice, receivers that have been unable to download the applicationsin the requisite time cannot benefit from the associated interactiveservices. Now, several factors might compromise the local availabilityof these applications: insufficient storage space, overly restrictedbandwidth, failed prior connection to a network (for example theInternet) for downloading, etc.

Document EP-0989743 discloses a method of transmitting application datain a digital transport stream, these data relating to several services.An application data table, also transmitted, contains information aboutthe applications transported in each service. This table enables inparticular a decoder to decide whether or not to maintain applicationswhen switching from one service to another (§[0148]), or whetherdownload applications not yet present in the decoder but required by anew service (§[0121]).

Prior document WO-01/31920 describes a technique for managing multipleapplications in a digital network, according to which a virtualapplication table (“VAT” table) is communicated to terminals. The latterare moreover furnished with authorization levels fixed by amultiapplications manager. On the basis of this information, eachterminal is capable of constructing a local VAT table, which indicatesthose applications that the terminal must be furnished with, bydownloading (p. 28, 1.3-27).

These latter two embodiments necessitate table tracking, management andutilization, which entails a relatively high level of complexity.

International application WO-00/64172 teaches a method for performing orotherwise a predefined action in a receiver, for example for selectingthe display of information, as a function of the contents of triggersreceived by this receiver. This display is different depending onwhether a predefined rule does or does not apply to the triggersreceived.

This technique requires that the management of the triggers be preciselycoordinated with the chosen display schemes.

Patent US-2002/0059623 discloses a file system with dual mode in atelevision of a subscriber network. This system is designed to use localdata when they are available and remote data (by downloading) in theconverse case. The data required for services can be obtained beforehandby the receivers and be stored locally in the form of data relating tohyperlinks (§[0107]). Upon the execution of a corresponding service, alocal application verifies the presence of these data in local memoryand proposes to the user the execution of an improved version of theservice using the hyperlinks (§[0109]).

Patent U.S. Pat. No. 5,966,120 describes a method for combining anddistributing data with a pre-formatted real-time video. In a receiver,an augmented video programme is created by inserting selected portionsof auxiliary data into a selected primary video programme. Theseauxiliary data may be stored beforehand in the receiver, so as to beutilized subsequently at the requisite time.

Prior document WO-02/32139 relates to systems and methods for providingmedia content on demand, for example on-demand video or audio content,or electronic publications. An interactive television furnished withappropriate means can retrieve further content corresponding to suchselected media content, either at the same time as the latter isdespatched, or by prior downloading (p. 42, 1.31-33). In the lattercase, the interactive television is capable of also retrievinginformation associating the further content with the media content (p.43, 1.9-14). The mode of display of the further content with respect tothe media content may optionally be chosen by the user (p. 45, 1.4-7).

The potentialities of these latter three techniques remain restricted inpractice to the displaying of small supplementary fields on the screen,added to the displaying of the base service, or to the introduction ofsequences such as short advertising inserts.

SUMMARY OF THE INVENTION

The present invention relates to interactive television and transmittingprocesses (notably broadcasting) enabling the execution of sophisticatedapplications, while considerably reducing the risks of nontriggering ofthe applications.

The processes of the invention may be implemented in a reliable manner,without needing excessive resources.

The invention also relates to devices associated with these processesand offering the same advantages: interactive television receiver,digital television terminal and programme transmitting station, as wellas corresponding computer programs.

The invention therefore relates to an interactive television processapplicable to a system where at least one or more transmitting stationstransmit programmes to receivers. This process comprises:

(a) reception in one of the receivers, of a startup application and of anormal application and triggering of the startup application causingexecution of steps b) to d) hereinbelow;

(b) testing for the presence in a memory of the said receiver of atleast one file of additional data;

(c) in the absence of this file or of these files of additional data inthe memory, starting up of the normal application;

(d) if the file or files of additional data are present in the memory,starting up of an improved application using these files of additionaldata.

The expression “interactive television” is understood to mean atelevision allowing either interactivity between the broadcastingstation and the receivers, by virtue of a return path, or localinteractivity at the level of the receivers or of terminals downstream,or both:

The term “application” designates moreover a functional assemblydesigned to be executed at the level of receivers and/or of terminalsdownstream, in interaction with a user, preferably in a format renderingit suitable for being broadcast over a network. This functional assemblycan in particular include content, in particular of audio and/or videotype, software instructions and/or description pages (for example HTMLor MHEG).

The distinction between startup normal and improved applications is of afunctional nature, each of these applications fulfilling a specificrole. However, in practice, they may be merged into functionalities ofone and the same application, a kernel of which is designed for startup,and provided with modules dynamically linked to the kernel so as toallow normal or improved operations. Hybrid embodiments with twoapplications instead of one or of three may also be beneficial (anapplication for startup and normal operations or an application forstartup and improved operations).

Further, several improved applications may also be provided likewise,that are respectively associated to the presence or the absence ofseveral addional data files.

Surprisingly, the process of the invention makes two distinctapplications, offering variable levels of information, availablesimultaneously to the receivers. It is at the receiver level, as afunction of the data available in memory, that the choice is madebetween these two applications. This approach contrasts with the knownmethods, which provide for complete unavailability of an application inthe case where the receiver is not able to execute it, and which are forthis reason centred around the adaptation of the execution capabilitiesof the terminals. It may offer great flexibility of implementation andof execution.

By way of illustration, the interactive television process isimplemented in respect of an automobile advert. In the versionassociated with the normal application, photos of cars for sale areshown statically on the screen, while superimposing, in display windows,information relating to the features of the vehicles for sale (screenmixing text and light graphics).

On the other hand, in the version associated with the improvedapplication, the television viewer is presented with video sequenceswith inlaid buttons, which make it possible to navigate from onesequence to another. A menu bar at the bottom of the screen makes itpossible to change stream so as to view and/or hear recounted, specificfeatures of the car.

More generally, the improved application advantageously expresses asvideo and/or sound sequences, elements expressed in a textual manner bythe normal application.

The transmission of the programmes from the transmitting stations to thereceivers is preferably done through broadcasting.

The receivers can consist of user terminals, or optionally of pooled ornetworked systems, able to make information in memory available for aplurality of terminals. In the latter case, the startup test and itsside branches are implemented at the level of these systems, upstream ofthe terminals.

In a first form of use of the startup application, the latter executessteps b) to d) itself. The test and selection instructions for theapplication to be started up are therefore controlled directly by thebroadcasting station. In a second form of use of the startupapplication, the test and selection instructions are implementedlocally, at the level of the receivers. The startup application thenonly has a role of triggering these functionalities. The implementationof these latter in a receiver may be performed by initial downloading(via the Internet or via a general broadcast), or by direct installationin the receiver of an appropriate module.

Preferably, it is possible to “force” startup of the normal application,even when the files of additional data are available locally. Thus, auser can in certain cases avoid possible problems of slowdowns or ofdisplay (overloaded memory, required version of the plugware or plug-innot available, etc.), by using just the elementary version of theapplication.

The process of the invention advantageously comprises the followingprior steps, the transmitting station comprising at least one link forbilateral communication with the receivers:

e) reception of a message proposing loading of the files of additionaldata into the receiver;

f) acceptance or refusal by a user of the receiver, of the proposedloading;

g) in case of refusal, exiting from the present process;

h) in case of acceptance, automatic downloading of the files ofadditional data which are usable subsequently by the startup application(A2) into the receiver, via the bilateral communication link;

i) recording in the said memory of the said receiver, of the files ofadditional data.

One of the objects of the invention may thus be to provide the user withthe possibility of accepting or of refusing the loading of data possiblyof various types (software, video and/or audio streams, pictures,alphanumeric information) and in this way to offer him several levels ofpayback of the application, depending on the presence of otherwise ofthese additional data.

In another advantageous form of downloading of the files of additionaldata, the return path is not used and the user interacts locally withthe receiver to indicate that he wishes to obtain an improved version ofthe application. The receiver then automatically obtains the files ofadditional data from information communicated by the transmittingstation with the loading proposal message. For example, the download isperformed via the Internet, by broadcasting in a specific stream, or bya broadband stream via a DSL network.

In yet another form of downloading of the files of additional data, theuser downloads them spontaneously from a communications network, such asfor example the Internet. He then needs to be informed sufficiently inadvance of the availability of the information and of their location(for example by means of a programme guide, or of a transmitted advert).

Before step f), there is advantageously provision for the reception, bythe receiver, of at least one cue regarding the contents of the files ofadditional data, this cue or cues preferably being chosen from among asize, a subsequent date of use, a date of expiry or of validity of theadditional data, a date on which the additional data will be used, abroadcasting channel which will use the additional data, and adownloading address.

Before step h), there is advantageously provision for the user toindicate a choice of immediate downloading or of deferred downloading ofthe files of additional data.

It is also beneficial during step e), for the reception of the proposalmessage to be effected upon the reception of an application of the sametype as the improved application.

According to a variant embodiment, the files of additional data containthe improved application. Alternatively, there is provision, during stepa), for the user to also receive the improved application.

Moreover, the process of the invention preferably comprises a step ofautomatic erasing of the contents of the memory. It is also possible toprovide for an automatic erasure system. A date of erasure is thenadvantageously associated with the files of additional data and theerasure step comprises a periodic operation of reading this date and anerasure operation when this date is reached. In another form of erasureof the contents of the memory, this erasure step is triggered by theuser or by a command remotely controlled from the broadcasting stationfor example.

It should be noted that the files of additional data may equally wellcontain one or more pieces of software, video data, pictures, sound or acombination of these types of data.

Moreover, the invention advantageously implements an interactivetelevision process applicable to a system where at least onetransmitting station comprises at least one bilateral communication linkto receivers. This process comprises the following steps:

a) sending of a message proposing loading of at least one file ofadditional data by a transmitting station to the receivers, with a viewto an optional improvement of an application intended to be executedsubsequently;

b) and upon acceptance by a user of one of the receivers, of theproposal message loading proposal, transmission to this receiver of thefiles of additional data.

This process, which is especially appropriate for the execution of theprocess defined above, preferably complies with the latter's schemes.

There is advantageously provision for the reception by a return path ofan acceptance message originating from the user terminal, then thetransferring of the additional data by this return path.

The invention applies also to an interactive television receivercomprising means for testing for the presence in a memory of the saidreceiver, of at least one file of additional data.

According to the invention, this receiver also comprises:

-   -   means of reception of a startup application and of a normal        application,    -   and means of starting up the normal application in the absence        of the files of additional data in the said memory and of        starting up an improved application if the files of additional        data are present in the memory.

This receiver is preferably designed to implement an interactivetelevision process in accordance with any one of the forms of theinvention. It is preferably furnished with a memory module capable ofrecording the files of additional data.

The subject of the invention is also a digital television terminal,characterized in that it comprises an interactive television receiveraccording to the invention.

Moreover, the invention applies to a process for transmittingapplications by a transmitting station to interactive televisionreceivers.

According to the invention, these applications comprise a startupapplication and a normal application, the startup application beingintended to cause a test for the presence in a memory of at least one ofthe receivers, of at least one file of additional data, as well as tostart up the normal application in the absence of these files ofadditional data and to start up an improved application using thesefiles of additional data if these files are present.

This transmitting process preferably is intended to implement theinteractive television process in accordance with any one of the formsof the invention.

The invention also pertains to a station for transmitting programmes tointeractive television receivers. According to the invention, itcomprises means of production and of transmission of at least onemessage comprising a startup application and a normal application Thestartup application is intended to cause a test for the presence in amemory of at least one of the receivers of at least one file ofadditional data, as well as to start up the normal application in theabsence of these files of additional data and to start up an improvedapplication using the files of additional data if these files arepresent.

This transmitting station is preferably intended to implement thetransmitting process according to the invention.

A further subject of the invention is a computer program productcomprising program code instructions for the execution of the steps ofthe process according to any one of the forms of the invention when thisprogram is executed on a computer. The expression “computer programproduct” is understood to mean any realization of a computer program, itmay be devised not only for storage media (cassettes, disks, etc.) butalso for signals (electrical, optical, etc.).

BRIEF DESCRIPTION OF THE DRAWINGS

The various subjects characteristic of the invention will be moreclearly apparent in the description which follows and in the appendedfigures which represent:

FIG. 1, a diagram illustrating the principle of the process of theinvention;

FIGS. 2 a and 2 b, flowcharts of an exemplary use of the process of theinvention;

FIG. 3, an exemplary implementation of the process forming the subjectof the flowcharts of FIGS. 2 a and 2 b;

FIGS. 4, 5 and 6, examples of information viewed by the user within theframework of the process of the invention;

FIG. 7, a flowchart of another exemplary process according to theinvention;

FIG. 8, an exemplary implementation of the process of FIG. 7;

FIG. 9, a flowchart illustrating a procedure for erasing the additionaldata in memory of a user terminal;

FIGS. 10 and 11, exemplary embodiments of user terminals enabling theinvention to be employed.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, the principle of the invention will therefore bedescribed.

A broadcasting station communicates in an interactive manner with one ormore digital television user stations, also called reception terminals.Such a terminal must be able to receive, decode and display on a screencontent of audiovisual and application package types, and is associatedwith a storage module allowing the local storage of the content.

As is represented in FIG. 1, the process provides for the followingsteps:

Step 1: Transmission by the broadcasting station and execution by theterminal of a first so-called validation application A1, through whichit will be possible to validate the loading and the storage of files ofadditional data;

Step 2: Transmission to the terminal and acquisition by the latter offiles of additional data, either by recording of these transmittedfiles, or by downloading from a server using a return path;

Step 3: Broadcasting and execution of a second so-called startupapplication A2 and testing for the presence of the files of additionaldata:

-   -   if the files of additional data are absent, starting up of a        normal application A3,    -   if the files of additional data are present, starting up of an        improved version A4 of the application, using the files of        additional data;

Step 4: Execution of the application (normal version A3 or improvedversion A4);

Step 5: Deletion of the files of additional data after an expiry date,or upon a particular command from the user or from the broadcastingstation.

Referring to FIGS. 2 a, 2 b and 3, a more detailed exemplary use willnow be described. According to this example, the files of additionaldata contain data making it possible to carry out in the required timean improved application, but do not contain the latter itself.

As represented in FIG. 2 a, the application A1 is broadcast and isloaded into the user terminal. This application is broadcast during anormal transmission. It constitutes an interrogation and validationapplication destined for the user.

By way of illustration, the validation application A1 is broadcastduring a trailer that presents a forthcoming event. For example,tomorrow afternoon, the “Tour de France” cycle race will reach Savoy. Onthis occasion, the service provider broadcasts the trailer with which aninteractive application is associated, the aim of which is to entice thetelevision viewer so that he authorizes the loading of the additionalcontent.

FIG. 4 illustrates the interactive application proposed during a trailerrelating to the coming broadcast of a leg of the Tour de France. Thescreen of the terminal comprises two zones Z1 and Z2 allowing the userrespectively to register or otherwise his interest in the applicationproposed.

The user will possibly have been informed of the content transfer time,of the possible unavailability of his terminal or of the return path andwill optionally be able to choose the means by which he wishes toacquire this content.

He will therefore be able to authorize the storage of additional contenton his appliance or on his network. It is this that is indicated in FIG.2 a in the form of the question “USER AGREES?”.

If the user is not interested in the proposed application, and thereforeif he does not agree to receive it, the procedure comes to an end. Onthe other hand, if he does agree, he responds positively and the systemprepares itself to send him one or more files of additional data.

Beforehand, but this is not absolutely necessary, the broadcastingstation transmits information about the contents of the file ofadditional data, such as configuration parameters enabling the terminalto download the contents from a URL or to record it (broadcastingservice, time of broadcast, etc.), but also the size of the additionaldata. Depending on this information, the user responds if he agrees toreceive the files of additional data. If not, the procedure comes to anend. In the case of a positive response, the system asks the user forthe mode of loading that he wants (“MODE OF LOADING?”). Specifically,with the information emanating from the application, the terminal willbe able either to download the content from a URL (standing for“Universal Resource Locator”) address by virtue of the return path, orto programme a timer to record a broadcast service that will contain theadditional content. This additional content may be broadcast at night,or on a service dedicated to the broadcasting of additional content.

In a preferred deployment, however, the user is not requested a secondand a third time after having given his agreement to the storage ofadditional content, in order to indicate whether he is still inagreement in view of the information regarding the files of additionaldata. In this variant, the download decision is taken automatically atlocal level, taking account of the configuration of the terminal and/orof the files acquisition network. This configuration is for examplespecified beforehand by the user, in the course of a preliminaryinstallation phase.

The file or files of additional data are then stored on a storagefacility (hard disk for example) that may be integrated into theappliance, or on an external storage facility.

In the case of external storage, the connection between the terminal andthe external storage facility is preferably effected using a standarddigital domestic bus with the associated protocols (Firewire and HAVifor example) but may also be effected in a proprietary manner.

A directory in which all the additional content is stored is defined.

As is represented in FIG. 2 a (“RECORDING IN MEMORY”), the files ofadditional data are recorded in memory.

Thereafter, a certain time after the broadcasting of the validationapplication A1 and after a delay sufficient to allow the terminal tofinalize the acquisition of the files of additional data, the startupapplication A2, the normal application A3 and the improved applicationA4 are broadcast on the terminal (see FIGS. 2 b and 3).

Next, the startup application A2 is executed on the user terminal.

The presence of the files of additional data is then tested for (“FILESIN MEMORY?”).

In the case where the files are not in memory, the system triggers thestarting up of the normal application A3.

In the case where the files of additional data are present in full inmemory, the system proceeds to the starting up of the improvedapplication A4.

Optionally, the user has the possibility however of in this casechoosing the normal application A3 rather than the improved applicationA4 (see FIG. 2 b).

FIG. 3 represents an exemplary implementation according to which thefiles of additional data contain only data (video, audio, pictures). Thevarious previous steps are found again in this figure:

1. broadcasting of the validation application A1;

2. broadcasting on request and recording in a memory facility of a userterminal of additional content (files of additional data);

3. broadcasting of the normal application A3 and of the improvedapplication A4 with the startup application A2;

4. starting up of the improved application A4.

FIG. 5 represents an example corresponding to the message of FIG. 4(selection of zone Z1), of an improved application where the vignette Vto the right of the text represents a video sequence. The user canoptionally view it in full screen mode by validating through anappropriate actuation.

FIG. 6 shows an exemplary normal application also provided for inassociation with the message of FIG. 4 (selection of zone Z2).

Referring to FIGS. 7 and 8, another exemplary implementation of theprocess of the invention will now be described. In this example, theprocedure for proposing files of additional data to the user and that heload them into the user terminal is the same as that which was describedin conjunction with FIG. 2 a and will therefore not be described again.On the other hand, the files of additional data contain the improvedapplication A4, this not having been the case previously.

As is represented in FIGS. 7 and 8, the normal application A3 and thestartup application A2 form the subject of a broadcast and of a loadinginto the user terminal. As previously, the test in memory for the fileor files of additional data is carried out. If these files are not inmemory, the normal application A3 is started. If these files are inmemory, the improved application A4 contained in the files of additionaldata is loaded into an execution memory (“LOADING OF A4”) and thenstarted (“STARTING OF A4”)—unless the user possibly decides to choosethe normal application A3.

The possibility should be noted of using a cache to store the normalapplication A3 broadcast before the startup application A2.

Moreover, the invention makes provision to delete the files ofadditional data from the memory of the user terminal, thus freeing someroom on the storage device and avoiding its saturation.

For this purpose, an expiry data is associated with each file ofadditional data, thus allowing the terminal to delete files whose expirydate has elapsed. This possibility is indicated in FIGS. 1, 3 and 8.

The deletion from memory of the recorded files of additional data mayalso be ordered by the user himself or remotely by the broadcastingstation.

FIG. 9 represents a flowchart of a process of programmed deletion of thefiles of additional data recorded in the memory of a user terminal.

During the loading of a file of additional data, an expiry date isassociated with this file either by the broadcasting station, or bysystem, or by the user. This date is recorded in a zone of a memorytable together with the address of the corresponding file of additionaldata. Periodically, the system explores the table, from the firstaddress of this table (i=0) to the last zone of the table (“LASTELEMENT?”). With each zone read, the expiry date is compared with theday's date. If it is not greater than the day's date, the system readsthe contents of the next zone by indexing the table (“i=i+1”).

If the expiry date is greater than the day's date, the file ofadditional data is deleted from the memory.

When all the zones have been explored, the system stops.

FIGS. 10 and 11 represent user terminals making it possible to employthe invention. These devices comprise a central processing unit which isconnected to a programme memory and which can receive commands from aremote control interface. The central processing unit manages a screendisplay device or OSD (standing for On-Screen Display) and anaudio/video interface for displaying transmissions on a screen.

In FIG. 10, reception is effected by a tuner and by an antenna making itpossible to pick up transmissions broadcast over the airwaves, as wellas by a modem connected (telephonically for example) to a serviceprovider or to a broadcasting station and linked to the centralprocessing unit. A device for recording additional data makes itpossible to store the files of additional data in the user terminal'sown memory, called “STORAGE of additional data”.

In FIG. 11, a digital network interface of the user terminal isconnected by a communication bus to a network tuner, to a networkstorage device for storing additional data and to a modem.

The terminal of FIG. 11 forms part of a network of terminals for whichthe files of additional data are stored in common by means of thenetwork storage device, which comprises for example a recording moduleand an appropriate storage space. The reception tuner and the modem arealso common to the network. The assembly is interconnected by thecommunication bus. The files of additional data are therefore receivedand stored by the network storage device by way of the tuner and of themodem.

1. Interactive television process applicable to a system where at leastone transmitting station transmits programs to receivers, the processcomprising: a) reception in one of said receivers, of a startupapplication and of a first application, wherein a triggering of saidstartup application, where said startup application performs a test,causes an execution of steps b) to d); b) testing for a presence in amemory of the one of said receivers of at least one file of additionaldata; c) in the absence of said file of additional data in said memory,starting up of the first application; d) if said file of additional datais present in said memory, starting up of a second application, saidsecond application using said file of additional data, where each ofsaid applications is a functional assembly designed for execution at thelevel of the one of said receivers.
 2. Interactive television processaccording to claim 1, wherein, with said transmitting station comprisesat least one link for bilateral communication with said receivers, saidprocess comprises the following prior steps: e) reception of a messageproposing loading of said file of additional data into the one of saidreceivers; f) acceptance or refusal by a user of the one of saidreceivers, of the proposed loading; g) in case of refusal, exiting fromthe present process; h) in case of acceptance, automatic downloading ofsaid file of additional data which is usable subsequently by saidstartup application into the one of said receivers, via said bilateralcommunication link; i) recording in said memory of the one of saidreceivers, of said file of additional data.
 3. Interactive televisionprocess according to claim 2, comprising, before step f), the reception,by the one of said receivers, of at least one cue regarding the contentsof said file of additional data, said cue preferably being chosen fromamong a size, a subsequent date of use, a date of expiry or of validityof the additional data, a date on which the additional data will beused, a broadcasting channel which will use the additional data, and adownloading address.
 4. Interactive television process according toclaim 2, comprising, before step h), a step in the course of which theuser indicates a choice of immediate downloading or of deferreddownloading of said file of additional data.
 5. Interactive televisionprocess according to claim 2, wherein during step e), the reception ofthe proposal message is effected upon the reception of an application ofthe same type as the second application.
 6. Interactive televisionprocess according to claim 1, wherein said file of additional datacontains an additional application.
 7. Interactive television processaccording to claim 1, wherein during step a), the one of said receiversalso receives said second application.
 8. Interactive television processaccording to claim 1, comprising a step of automatic erasing of thecontents of said memory.
 9. Interactive television process according toclaim 8, wherein a date of erasure is associated with said file ofadditional data and in that the erasure step comprises a periodicoperation of reading this date and an erasure operation when this dateis reached.
 10. Interactive television process according to claim 1,wherein said file of additional data contains data chosen from among atleast a piece of software, video data, pictures, sound and a combinationof these types of data.
 11. Interactive television receiver comprisingmeans for testing for the presence in said memory of the one of saidreceivers, of at least one file of additional data, comprising: means ofreception of said startup application and of said first application; andmeans of starting up the first application in the absence of said fileof additional data in said memory and of starting up a secondapplication if said file is present in said memory, said secondapplication using said file of additional data, where each of saidapplications is a functional assembly designed to be executed at thelevel of the one of said receivers, and said receiver preferably beingdesigned to implement an interactive television process in accordancewith claim
 1. 12. Digital television terminal, comprising an interactivetelevision receiver according to claim
 11. 13. Process for transmittingapplications by a broadcasting station to interactive televisionreceivers, wherein each of said applications is a functional assemblydesigned to be executed at the level of said receivers and saidapplications comprise said startup application and said firstapplication, said startup application being intended to cause said testfor the presence in a memory of the one of said receivers, of at leastone file of additional data, as well as to start up the firstapplication in the absence of said file of additional data and to startup a second application if said file is present, said second applicationusing said file of additional data, said transmitting process preferablybeing intended to implement said interactive television process inaccordance with claim
 1. 14. Station for transmitting programs tointeractive television receivers, comprising means of production and oftransmission of at least one message comprising said startup applicationand said first application, said startup application being intended tocause said test for the presence in a memory of at least one of saidreceivers of at least one file of additional data, as well as to startup the first application in the absence of said file of additional dataand to start up said second application if said file is present, saidsecond application using said file of additional data, where each ofsaid applications is a functional assembly designed to be executed atthe level of the one of said receivers and said transmitting stationpreferably being intended to implement the transmitting processaccording to claim 13.